Circuit breaker



M. H. ROWE CIRCUIT BREAKER Sept. 5, 1939.

Filed April 1, 1957 ,2 Sheets-Sheet l Sept. 5, 1939.

M. H. RowE CIRCUIT BREAKER Filed April 1, 1937 2 Sheets-Sheet 2 .Aw l" 7.141,7

@www

Patented' Sept. 5, 1939 UNITED STATES PATENT OFFICE CIRCUIT BREAKER Dallas, Tex.

Application April 1, 1937,' Serial No. 134,217

14 Claims.l (Cl. 200-124) This invention relates to new and useful improvements in circuit breakers.

One object of the invention is to provide an imp roved electrical circuit breaker which is particularly adapted for use in the usual fuse box being substituted for the usual plugtype fuse.

An important object of the invention is to provide an improved electrical device adapted to be inserted into the usual electrical receptacle and which acts as a circuit breaker to break the electrical circuit upon a short circuit orv overload, and which is arranged to be reset to circuit closing' position by merely removing the device partially from the receptacle, whereby the.,

electrical current is not owing through the device during the resetting thereof, which eliminates spark, as well as danger of electrical shock to the operator during the resetting operation.

Another object of the invention is to provide an improved' circuit breaker of the character described having a latch member held in circuit closing position by f usible material so that upon overload or short circuit said material is melted or liqueed to permit the latch to be disengaged tofopen the circuit; with means for automatically restoring the latch to its normal position While the fusible material is solidifying through cooling, whereby the latch may be reset to circuit closing position and the device repeatedly used.

Still another object of the invention is to provide an improved circuit breaker of the character described wherein the setting of the device to circuit closing position] is directly controlled by the insertion of the device into an electrical receptacle, or other operating position.

' Still another object of the invention is to, provide an improved device ofthe character described, wherein a movable yoke member is arranged to close the electrical circuit through the device with an improved latch for holding the same in circuit closing position, said latch being so constructed as to produce a snap action,

thereby minimizing' danger of spark and prollonging the life of the device.

A construction designed to carry out the invention Will be hereinafter described, together with other features of the invention.

Theinvention will be more readily understood from a reading of the following specification and mounted within an ordinary electrical receptacle, the latter being shown in section,

Figure 3 is a transverse vertical sectional view of the part shown in Figure 2 and showing the latch in circuit closing position,

Figure 4 is a viewY similar to Figure 3 with the latch in its disengaged position,

. Figure 5 is a view similar to Figure 3, and taken at right angles to said figure, with the device in circuit closing position,

Figure 6 is a view similar to Figure 5 with the electrical circuit broken,

Figure 7 is a transverse vertical sectional view of a' circuit breaker as shown in Figure 1 and with the part in circuit closing position,

Figure 8 is a plan view of the circuit breaker in circuit closing position,

Figure 9 is a similar view showing the designation visible in the top of the circuit breaker when the circuit. therethrough is broken,

Figure 10 is a bottom View of the circuit breaker,

Figure 11 is a horizontal cross-sectional view, taken on the line II-II of Figure 3,

Figure 12 is a horizontal, cross-sectional view, taken on the line I2-I2 of Figure 3,

Figure 13 is a horizontal, cross-sectional view, taken on the line I3--I3 of Figure 7,

Figure 14 is an isometric view of the connecting yoke and latch, and

Figure 15 is a detail view showing the movement of the latch member when the fusible material is heated.

In the drawings, the numeral I designates a hollow cylindrical shell or housing which is constructed of glass, or other electrical non-conducting material. One end of the housing is open while the opposite end is closed by an end wall II, which wall is provided with an internal axial recess I2. The upper end of the end wall may also be recessed as shown at Il'. The end wall is preferably made integral with the housing or shell and an annular outwardly extending ange I3 is formed at this closed end of the shell. The shell or housing is substantially of the same diameter as the ordinary plug-type fuse, whereby it may be inserted in the usual electrical receptacle- I4 which receives such fuse. An insulating block I constructed of .a suitable electrical nonconducting material, such as Bakelite, is arranged to be inserted into the open end of the shell or housing IU. The block is provided with an external shoulder I6 which engages the end of the housing and as clearly shown in Figures 3 to 7 the upper end of the block is received Within the housing or shell. When said block is inserted within the shell, an annular metallic collar Il is threaded on the exterior surface of the block and also on the exterior surface of the lower end of the shell. The collar Il is provided with an inturned annular flange I8 which engages an external shoulder I9 formed on the block I5. With such arrangement the metallic collar Il serves to connect the shell I with the block I5. 'Ihe lower end of the block below the collar I'I is tapered or reduced toward its center. 1t will be manifest that thebiock and sheu when connected by the collar I'l provide a device which is substantially of the same size and shape as the ordinary plug-type fuse.

'I'he threads of the collar I'l are formed by a pressing operation, whereby said collar is provided with external as well as internal threads. These external threads may be utilized for screwing the device into the usual electrical receptacle I4 which is provided for the reception -of plug-type fuses. It is noted that the collarv Il may be riveted or otherwise secured to the shell II) and block I5 and the invention is not to be limited to threading said collar thereon although this latter method makes for easy disassembling of the device.. v

For conducting electrical current through the circuit breaker, the lower reduced end of the block I5 is provided with a circular contact 20, and this contact hasan upwardly extending contact bar 2| integral therewith (Figures 5 and 6) The contact bar 2| extends upwardly through the block I5, being preferably molded therein and the upper end of this bar terminates at a point substantially in horizontal alinement with the external shoulder I6 ofthe block. The extreme upper end of the ba'r 2| extends into an opening 22 which is provided in the block and' which is substantially rectangular in cross-section (Figure l2). The opening 22 extends from the top of the block |5 to a point below the upper end of the contact bar 2|. Manifestly, when the device is inserted into the usual electrical receptable I4, the circular contact 20 at the lower end of the block I5 will engage the usual axial contact A of the receptacle whereby the electrical current may ow upwardly through the bar 2| ywhich is integral with the contact 20.

Diametrically opposite the rectangular opening 22 is a similar opening 23 which extends vertically of the block I5 (Figures 5 and 6). A

short contact bar 24 has its upper end extending into the lower end of the opening 23. The lower end of the bar 24 is bent outwardly so as to extend radially to the outer surface of the block I5. 'Ihe bar 24 is then bent upwardly so as to extend contiguous to the inner surface of the metallic collar I'l. The bar 24 is of course preferably molded within the block |5 and is further held in place by the collar It willl be obvious that with the device inserted within the usual receptacle I4, the current will ilow from the metallic insert collar B of said receptacle through the collar I1 and then 'through the 'arm 24. 'Ihe other side of the electrical circuit to the receptacle is of course connected to the bar 2| through the contact 28 at the bottom of the block. Therefore, by connecting the bar 2| with the bar 24, the electricakcircuit through/the device may be completed.

For connecting the bars to complete-the circuit through the device, a yoke 25 is provided. This yoke is clearly shown in Figure 14 and includes vertical yoke arms 26 connected by a semi-circular connecting lmember 2l, whereby the arms move together. A laterally directed arm 28 extends from the center of the connecting member 2l and has its extreme outer end oiset to provide an indicator 29. This olset portion of the arm 28 has the word 01T printed thereon. The yoke arms 26 are adapted to be inserted in the rectangular openings 22 and 23 in the block I5 and when moved to a lowermost position, have their lower ends overlapping and engaging the upper end of the bars 2i and 2li, whereby an electrical connection is obtained between said bars.

For guiding the yoke 25 in its vertical movement as the yoke arms 26 engage or disengage the bars 2| and 24, a plunger or stem 30 is slidably mounted in an axial bore 3| provided in the block I5. The contact 28 mounted on the reduced lower end of the block is provided with a central opening 2D to permit the plunger 30 to extend therethrough. The upper end or portion of the plunger 30 extends through a slot 29 provided in the arm 28 of the yoke 25. It is noted 'that the slot 29 of said arm is in axial alinement with the bore 3| of the block. The extreme upper end of the plunger 30 is formed with an integral collar 32 and this collar limits the upward movement of the yoke 25 on the plunger. The bore 3| of the block I5 is enlarged at its upper en d 'as shown at 3|', whereby an internal annular shoulder 33 is formed within the bore of the block. -A coiled spring 34 is confined between this shoulder and the underside of the arm 28 which is secured to the yoke 25, and this spring exerts its pressure to constantly urge the yoke 25 upwardly with relation to the plunger 30.

For holding the yoke 25 in its lowermost position within the openings 22 and 23, whereby its arms 26 contact the bars 2| and 24 and thereby maintain the device in circuit closing position,l an angular latch member 35 is mounted on said yoke. The latch member includes a laterally directed arm 38 and a vertically extending arm 37, as is clearly shown in Figure 14. The laterally directed arm of the latch member overlies the connecting member 21 and the arm 28 of the yoke and has its outer end provided with a slot 36' which slot is in alinement with and of the same size as the swinging movement with relation to the yoke.

To normally prevent the swinging movement of the latchv member 35 with relation to the yoke 25 a fusible material 40 covers the lug 38 and the opening 39 through which said lug extends. When this material is cool, it is a solid and acts as a bond to secure the latch member 35 to the yoke 25. However when this fusible material becomes heated, it melts or softens and an upward pressureagainst the outer end of the arm 36 of the latch member 35 will cause a swinging movement of the vertical arm 3l of said latch member.

.The vertical arm 31 extends downwardly into an opening 4| which is formed in the marginal portion of the block I5. 'Ihis opening is substantially rectangular in cross-section and has an inwardly projecting shoulder 42 formed at its lower end. The extreme lower end of the arm 31 o1 the latch member 35 is offset-to form a projection 43,

which projectionis arranged to engage beneath the shoulder 42 to hold the yoke 25 in its lowered position under tension of the coiled spring 34.

So long as the device is within the usual receptacle I4, it will be obvious that the plunger or stem 30 engaging the bottom of the receptacle will be forced upwardly into the upper end of thev casing or shell I or into the position shown .in Figures 3 to 6.. However, when the device is removed. from the receptacle |4 the plunger 30 is forced outwardly from the axial bore 3| of the block I5. This outward movement of the plunger or stem is produced by the action of a coiled spring 44 which is conned between the collar 32 on the stem and the .inner end of the wall II of the shell. This coiled spring has its upper end located within the recess I2 in said end wall and is stronger than the spring 34 located Within the bore of the block, whereby it may overcome the pressure of the latter spring. Obviously, when the device is within'areceptacle, the engagement of the plunger 30 with the lower end of the receptacle will move the plunger upwardly under tension of the spring 44. In operation, it will be assumed that the device is in circuit closing position and said device is removed from the usual receptacle I4, in which instance, the part would be in the position shown in Figure 7 with the latch member 35 having the lug at the lower end of its vertical arm 31 engaged beneath the shoulder 42 of the opening 4I. The fusible material 40 is (ifcourse solidified sincethe yoke and latch member are cool, whereby the latch member 35 is held in a fixed position on the yoke 25. With the lug 43 at the lower end of the arm 31 of said latch member engaged with the shoulder 42, the yoke 25 is held in its lowermost position as shown in Figures 3, and '7. In this position'the arms 25 of the yoke are within the openings 22 and 23 of the block I5 and have their lower ends engaging the upper ends of the Contact bars 2| and 24 whereby the electrical circuit through vthe device is complete. The coiled spring 34 which surrounds the plunger 30 within the bore 3| of the block I5 is of course under compression being held so by the engagement ofthe latching member with the shoulder 42. At this time the plunger is in its lowermost or extended position with the collar 32 of said plunger engaging the lateral arrn 36 of the -latch number 35. The plunger is held in this position by the coiled spring 44 which, as

has been stated, has a greater pressure than the spring 34.

When the block I5 and shell Ill are inserted into the usual receptacle I4 it will be evident that the outer end of the plunger 30 will engage the bottom of the receptacle and as the metallic collar |1on`"the block and shell is threaded into said receptacle, the plunger 33 is moved inwardly within the shell and bore 3| under tension of the spring 44. The plunger is of course made of a suitable electrical non-conducting material and by the time that the device is entirely within the socket or receptacle, the plunger has moved to its innermost or retracted position. This position is clearly shown in Figures 3 and 5 and the collar 32 on said plunger or stem has moved away from the latehing member 35 and yoke 25. So long as the device remains in the receptacle the plunger 30 remains in the same position with the spring 44 under tension.

Since the latch member 35 is constructed of av metallic electrical conducting material and connecting yoke 25, it will be obvious that the currentv flowing from the bar 2| through the yoke 25, and to the opposite Contact bar 24, will also flow through the latch member 35. Therefore, if a short circuit or overload occurs in the electrical circuit, the fusible material 40 will become heated which will result in a melting or softening of this material. As soon as this occurs, the pressure of the spring 34 which is constantly urging the arm 28 of the yoke 25 and the laterally directed arm 36 of the latch member 35 upwardly, will result in an upward swinging of the outer end of these arms. Since the latch member 35 may undergo a limited swinging movement on the yoke 25 when the fusible material is not solidified, it will be obvious that said latch member will be swung to the position shown in dotted lines in Figure 15. This swinging of the latch member will disengage the lug 43 from the shoulder 42 and will permit the spring 34 to move the yoke and latch upwardly to the position shown in Figures 4 and 6. The upward movement of the yoke and latch carried thereby is of course limited by. the collar 32 on the upper end of the plunger 30. When the yoke moves to its upper position the lower ends of its arms 26 are disengaged from the contact bars 2| and 24, whereby the electrical circuit through the device is broken.

The breaking of the electrical circuit permits the fusible material 40 to immediately solidify or harden, whereby the latch member 35 is again securely fastened to the'yoke 25. It is noted that since the lateral arm 3B of the latch member 35 strikes the collar 32 upon upward movement of the yoke, and also due to the fact that the spring 34 is urging the part upwardly, the normal position of the yoke is restored before the fusible material 40 hardens. Therefore it is assured that the latch member 35 is always fastened to the yoke 25 by the fusible material in the same position. When the yoke 25 is moved upwardly to the position shown in Figures 4 and 6, the offset indicator 29 which is formed on the outer end of the arm 28 of the said yoke lies. be-

neath the inner surface of the end wall |I, /fwhereby the indicia on said indicator is visible through said end wall, as clearly shown in Figure 9. This indicates to the operator that a short circuit or voverload. has occurred and that the electrical circuit through the device is broken.

In order to reset the latch member 35 so as to restore the yoke 25 to its circuit closing position, it is only necesary to unscrew the shell and block from the receptacle I4. As this is done the strong spring 44 acting against the upper end of the collar 32 of the plunger 3|) will force the plunger outwardly from the bore 3| of the block. The spring 44 is of course acting against the coiled spring 34 but since it is of a stronger pressure, it will easily overcome this spring. .As the plunger 30 moves outwardly of the block l5 it will be evident that the latch member 35 and yoke 25 will be moved downwardly toward the block. As soon as the shell ID is unscrewed suiiiciently from the receptacle to permit a complete projection of the plunger 30 from the block I5, the yoke 25 has moved to its lowermost position (Figure 7). By this time the vertical arm 31 of the latch member 35 has moved downwardly in the opening 4|, whereby the lug 43 at the lower end of said arm has been re-engaged with the shoulder 42. It is pointed out that it is not necessary to completely unscrew the shell l@ from the receptacle l! but only a partial removal of this shell from the receptacle will permit the plunger to complete its resetting operation. Of course, the amount of movement of the shell and block I with relation to the receptacle M- is dependent upon the space between the collar 32 and the upper end of th block' i5.

After the yoke and latch member have been reset as explained it is only necessary to return the shell i and block l5 into the receptacle whereby the plunger 3U is again returned to the position shown in Figure 5 and the device is again ready for operation. If a short, circuit is present in the electrical circuit, the fusible material d0 will again be heated immediately which will again release the yoke, moving the same to its uppermost position, whereby the operator is advised that a short circuit is present. If the disengagement of the latch member 35 Was due to an overload, the resetting of the device again closingr the circuit will remedy the trouble. With the construction set forth above, it will be evident that the resetting is automatically accomplished by the plunger 3D and the actuation of the plunger is controlled entirely by the position of the device within the receptacle or socket in which it is inserted.

What I claim and desire to secure by Letters Patent is:

1. A circuit breaker arranged to be inserted in an electrical receptacle including, an insulating block, electrical contacts mounted on said block, means for electrically connecting said contacts to close an electrical circuit through said circuit breaker, means for eiecting a disengagement'of said connecting means from the contacts when an overload or short circuit occurs in the electrical circuit, and means coacting with the v receptacle and for resetting the connecting meansto circuit closing position when the circuit breaker is partially removed from the receptacle.

2. A circuit breaker arranged to beA inserted in an electrical receptacle including, an insulating block, electrical contacts'mounted on said block, means for electrically connecting said contacts to close an electrical circuit through said circuit breaker, means for eiecting a disengage-v ment of said connecting means from the contacts when an overload or short circuit occurs in the electrical circuit, and means coacting with the receptacle and controlled by the position of the circuit breaker in the receptacle for resetting the connecting means to circuit closing position.

3. A circuit breaker arranged to be inserted in an electrical receptacle including, an insulating block, electrical contacts mounted on said block,

. means for electrically connecting said contacts to close anA electrical circuit through said circuit breaker, means for effecting a disengagement of said connecting means from the contacts when an overload lor short circuit occurs in the electrical circuit, means for resetting the connecting Ymeans to circuit closing position, and means mounted in the block and co-acting with the receptacle for preventing the resetting of said connecting means until the electrical connection between the contacts of the block and receptaclel is broken. l

4. A circuit breaker arranged to be insertedA into an electrical outlet receptacle including, an insulating block, electrical contacts mounted on said block, means for electrically connecting said contacts to close an electrical circuit therebetweenf-a latch carried by said connecting means "annees said block, means for electrically connecting saidl contacts to close an electrical circuit therebetween, a latch carried by said connecting means for holding said connecting means in circuit closing position and being maintained'in place by a fusible material, whereby an overload or short circuit softens said material to permit disengagement of the latch to effect a disengagement of said connecting means from the contacts, and means controlled by the position of the circuit breaker in the receptaclefor resetting the connecting means to circuit closing position.

6. A circuit breaker arranged to be inserted into an electrical outlet receptacle including, an insulating block, electrical contacts mounted on said block, means for electrically connecting said contacts to close an electrical circuit therebetween, a latch carried by said connecting means for holding said connecting means in circuit closing position and being maintained in place by a fusible material, whereby an overload or short circuit softens said material to permit disengagement of the latch to eiect a disengagement of said connecting means from the contacts, means for resetting the connecting means and latch to circuit closing position, and means mounted in the body and co-acting with the receptacle for preventing the resetting of said connecting means until the electrical connection between the contacts of the body and receptacle is broken.v

'7. A circuit breaker including, a shell, an insulating block mounted in the shell, said shell and block being arranged to be inserted in an electrical outlet -receptacleelectrical contacts mounted on the block having electrical connection with the receptacle when the shell and block are in operative position within said receptacle, means for electrically connecting the contacts to close an electrical circuit therebetween, a latch mounted on said connecting means for holding the latch in circuit closing position and adapted to undergo a limited swinging'movement with relation thereto, a fusible material at the point of connection between the latch and connecting means for normally holding the latch in a xed position thereon, said fusible material being softened when an overload or short circuit occurs to' permit swinging of the latch to disengage the same and effect a disengagement of'the connecting means with the contacts, and means for resetting the latch and connecting means to circuit closing position.

8. A circuit breaker including, a shell, an insulating block mounted in the shell, said shell and block being arranged to beinserted'in an electrical outlet receptacle, electrical contacts mounted on the block having electrical connection with the receptacle when the shell and block are in operative Aposition within said receptacle, means for electrically connecting the contacts to close an electrical circuit therebetween, a latch mounted on said connecting means for holding the latch in circuit closing position and adapted to undergo a limited swinging movement with relation thereto, a fusible material at the point of connection between the latch and connecting means for normally holding the latch in a xed position thereon, said fusible material being softened when an overload or shortv circuit occurs to permit swinging of the latch to disengage the same and effect a disengagement of the connecting means with the contacts, and means controlled by the position of the circuit breaker in the receptacle for resetting the connecting means to circuit closing position.

9. A circuit breaker including, a. shell, an insulating block mounted in the shell, said shell and block being arranged to be inserted in an electrical outlet receptacle, electrical contacts mounted on the block having electrical connection with the receptacle when the shell and block are in operative position within said receptacle, means for electrically connecting the contacts to close an electrical circuit therebetween, a latch mounted on said connecting means for holding the latch in circuit closingposition and adapted to undergo a limited swinging movement with relation thereto, a fusible material at the point of connection between the latch and connecting means for normally holding the latch in a fixed position thereon, said fusible material being softened when an overload or short circuit occurs to permit swinging of the latch to disengage the same and effect a disengagement of the connecting means with the contacts, means for resetting the latch and connecting means to circuit closing position, and means mounted in the block and co-acting with the receptacle for preventing the resetting of said connecting means until the electrical connection between the contacts of the block and receptacle is broken.

10. A circuit breaker including, a shell, an insulating block mounted in the shell, said shell and block being arranged to be inserted in. an electrical outlet receptacle, electrical contacts mounted on the block having electrical connection with the receptacle when the shell and block are in operative position within said receptacle,

means for electrically connecting the contacts to close an electrical circuit therebetween, a latch mounted on said connecting means for holding the latch in circuit closing position and adapted to undergo a limited swinging movement with relation thereto, a fusible material at the point of connection betweenv the latch and connecting means for normally holding the latch in a fixed position thereon, said fusible material being softened when an overload or short circuit occurs to permit swinging of the latch to disengage the same and eifect a disengagement of the connecting means with the contacts, means for resetting the latch and connecting means to circuit closing position, and a plunger slidable through the block and co-acting with the receptacle for preventing the resetting of the said connecting means until the electrical connection between the contacts of the block and the receptacle is broken.

11. A circuit breaker including, a shell, lan insulating block mounted in the shell, said shell and block being arranged to be inserted in an electrical outlet receptacle, electrical contacts mounted on the block having electrical connection with the receptacle when the 4shell and block are in operative position within said receptacle, means for electrically connecting the contacts to close an electrical circuit therebetween, a latch mounted on said connecting means for holding the latch in circuit closing position and adapted to undergo a limited swinging movement with relation thereto, a fusible material at the point of connection between the latch and connecting means for normally holding the latch in a fixed position thereon, said fusible material being softened when an overload or short circuit occurs to permit swinging of the latch to disengage the same and eiect a disengagement of the connecting means with the contacts, means for resetting the latch and connecting means to circuit closing position, and a plunger slidable through the block and co-acting with the receptacle for preventing the resetting of the said connecting means until the electrical connection between the contacts of the block and the receptacle is broken, said plunger being spring pressed and adapted to engage the latch and connecting means to reset the same to circuit closing position when the electrical connection between the receptacle and the contacts of the block is broken.

12. A circuit breaker arranged to be inserted into an electrical outlet receptacle including, an insulating block, electrical contacts mounted on said block, a yoke for electrically connecting said contacts to close an electrical circuit therebetween, a latch carried by said yoke for holding said yoke in circuit closing position and being y maintained in place by a fusible material, whereby an overload or short circuit softens said material to permit disengagement of the latch to effect a disengagement of said yoke from the contacts, and means for resetting the yoke and latch to circuit closing position.

13. A. circuit breaker arranged to be inserted into an electrical outlet receptacle including, an insulating block, electrical contacts mounted on said block, a yoke for electrically connecting said contacts to close an electrical circuit therebetween, `a latch carried by said yoke for holding said yoke in circuit closing position and being maintained in place by a fusible material, whereby an overload or short circuit softens said material to permit disengagement of the latch to effect a. disengagement of said yoke from the contacts, means for resetting the yoke and latch to circuitclosing position, and means mounted in the block and co-acting with the receptacle for preventing the resetting of said yoke until the electrical connection between the contacts of the block and receptacle is broken.

14. A circuit breaker arranged to be inserted into an electrical outlet receptacle including, an insulating block, electrical contacts mounted on said block, a yoke for electrically connecting said contacts to close an electrical circuit therebetween, a latch carried by' said yoke for holding said yoke in circuit closing position and being maintained in place by a fusible material, whereby an overload or short circuit softens said material to permit disengagement of the latch to effect a disengagement of said yoke from the contacts, means for resetting the yoke and latch to circuit closing position, and a plunger slidable through the block and co-acting with the recep- 

